Double Layer Research Articles

Secondary carbon skeletons constructed in porous carbon for electric double layer capacitors

In this work, a secondary skeleton was constructed by filling the larger spaces of porous carbon derived from passion fruit peels with glucose to created more carbon surface in same volume. The combined use of KOH activation and simultaneous etching of micropores on the carbon skeleton and secondary skeleton resulted in the preparation of porous carbon (PGC1-0.5) containing a large number of micropores. PGC1-0.5 have less total pore volume (0.987 cm3 g-1), but more micropore volume (0.821 cm3 g-1), different with 1.171 cm3 g-1, 0.668 cm3 g-1 of PGC1-0, which without glucose. Symmetric supercapacitor bases on PPGC1-0.5 have an obvious improvement in specific capacity (275.6 F g-1 (175 F cm-3), 0.1 A g-1) in 6M KOH electrolyte compared to PGC1-0 (215.2 F g-1 (121.5 F cm-3), 0.1 A g-1). Additionally, the device exhibits excellent cycling performance and retained 103% of its specific capacity after 10,000 cycles and notable reduction in transfer internal resistance in comparison to the sample without glucose. This study shows that filling space with glucose to reduce macropores is an effective method for adjusting the pore size distribution of porous carbon.

Electric Double Layer Capacitors: A Review

Electric Double Layer Capacitors: A Review

Analysis of Electroviscous Effect for Flow of Micropolar Fluids in a Nanochannel with Overlapping Electric Double Layers at High Zeta Potential.

Flows in nanofluidic channels under the influence of pressure gradient often lead to the overlapping of the electrical double layers (EDLs) augmenting the electroviscous effect. In this work, we analyze the electroviscous effect for the flow of a micropolar fluid in a parallel plate nanochannel, considering EDL overlapping and interfacial slip. Closed-form expressions of EDL potential, velocity, microrotation, yielded streaming potential, and volumetric flow rate are derived semi-analytically for high zeta potential without accounting for the Boltzmann distribution. We observe a significant change in streaming potential with inverse ionic Peclet number (R) for its lower values, and the range of streaming potential is more for thicker EDL. The micropolarity parameter does not have any influence on the streaming potential for weaker EDL overlapping at a lower R value. For thicker EDL, velocity decreases with the micropolarity parameter, while it increases drastically with interfacial slip. However, velocity shows a non-monotonic behavior with interfacial slip and micropolarity parameter for thinner EDL. The microrotation remains invariant with interfacial slip for thicker EDL, whereas its magnitude decreases with slip length for thinner EDL. Although the sensitivity of the flow rate on slip (Qs*) increases with R for thicker EDL, the behavior is non-monotonic for thinner EDL. Furthermore, Qs* varies non-monotonically with the micropolarity parameter at higher couple stress parameter values and vice versa. In fact, the volumetric flow rate is highly sensitive to slip for thicker EDL overlapping.

O-PHTHALALDEHYDE CROSS-LINKED CHITOSAN MEMBRANE AS A QUASI-SOLID-STATE ELECTROLYTE FOR SUPERCAPACITORS

This study reports a stepwise formation method of a chitosan membrane cross-linked with o-phthalaldehyde and its use as a polymer matrix in a quasi-solid-state-electrolytebased supercapacitor. The proposed method of cross-linking in chitosan solution and evaporation of the solvent yielded a homogeneous and durable chitosan-o-phthalaldehyde membrane, which, after dipping in an aqueous 2 M lithium sulfate solution, formed a quasi-solid-state-electrolyte (CS/OPAQSSE). The prepared CS/OPA-QSSE was then used in an electric double layer capacitor (EDLC) cell to study its electrochemical properties. The electrochemical performance of the EDLC cell was determined by using the electrochemical impedance spectroscopy, cyclic voltammetry and galvanostatic charging/discharging techniques. The results showed that the EDLC cell with the CS/OPA-QSSE is a fully functional and efficient device. The specific capacitance values calculated for the CS/OPA-QSSE EDLC (up to 115 F g–1) always surpassed the reference cell based on a commercial glass fibre separator Therefore, the proposed chitosan modification can be considered as a future alternative to produce other polysaccharide-based materials for electrochemical use.

Electrical Double Layer and In Situ Polymerization SEI Enables High Reversible Zinc Metal Anode.

Aqueous zinc-ion batteries (AZIBs) stand out among new energy storage devices due to their excellent safety and environmental friendliness. However, the formation of dendrites and side reactions on the zinc metal anode during cycling have become the major obstacles to their commercialization. This study innovatively selected Sodium 4-vinylbenzenesulfonate (VBS) as a multifunctional electrolyte additive to address the issues. The dissociated VBS- anions can not only significantly alter the hydrogen bond network structure of H2O in the electrolyte, but also preferentially adsorb on the surface of the zinc anode before H2O molecules, which will result in the development of organic anion-rich interface and alterations to the electrical double layer (EDL) structure. Furthermore, the ─C═C─ structure in VBS leads to the formation of an in situ polymerized organic anion solid electrolyte interface (SEI) layer that adheres to the surface of the zinc anode. The mechanisms work together to significantly improve the performance of Zn//Zn symmetric batteries, achieving a cycle life of over 1800h at 1mA cm-2 and 1 mAh cm-2. The introduction of VBS also enhances the cycling performance and capacity of Zn//δ-MnO2 full cells. This study provides a low-cost solution for the development of AZIBs.

N-(4-(1,3-benzothiazol-2-ylcarbamoyl)phenyl)isonicotinamide as corrosion mitigator for mild steel in 1 M HCl: A multifaceted study integrating synthesis, characterization, and molecular modelling

Newly synthesized, cost-effective corrosion inhibitor, N-(4-(1,3-benzothiazol-2-ylcarbamoyl)phenyl)isonicotinamide (BIA) was evaluated for mild steel/1M HCl interface. BIA showed a maximum inhibition efficiency of 90.40 % at 100 ppm and 303 ± 1 K, with efficiency increasing with concentration but decreasing with temperature. Inhibitor’s adsorption followed Langmuir isotherm via physicochemical interactions. Activation parameters revealed BIA retards both metal dissolution and hydrogen evolution held in unimolecular process. Potentiodynamic polarization (PDP) divulged BIA as a mixed-type, impeding charge-transfer. Electrochemical impedance spectra (EIS) confirmed BIA forms a protective double layer, blocking active sites at the interface. Surface analysis supported a protective film formation. Global and local reactivity descriptors using DFT/B3LYP/6-311G++(d,p) were calculated to relate inhibition efficiency with BIA’s electronic properties. Molecular dynamics simulation (MDS) showed an interaction energy of −224.7 kJ/mol between BIA and Fe(110) at 303 K, with Radial Distribution Function (RDF) showing bond lengths under 3.5 Å, confirming a chemical interaction. Theoretical results align with experimental data.

An environmentally sustainable ultrasonic-assisted exfoliation approach to graphene and its nanocompositing with polyaniline for supercapacitor applications

In the present work, a green high-yielding method for the preparation of graphene is introduced via ultrasonic-assisted liquid phase exfoliation (LPE) of graphite in a green solvent medium, since the common preparation method of graphene via graphite oxide is hazardous. A high concentration of 3.2 mg/ml graphene is achieved here in a comparatively short duration of 3 h ultrasonication. By using a mixed solvents strategy (acetophenone and isopropyl alcohol, 1:19 V/V), surface energy requirements needed for the exfoliation of graphite are satisfied here with acetophenone, where isopropyl alcohol further facilitated the exfoliation via non-conventional CH-π and OH-π interactions. Turbostratic graphene in high-yield (16 %) in a simple means of ultrasonic assisted LPE is the added attraction of the present procedure. The less-defective structure of graphene, its few-layered turbostratic nature, and edge functionalization of the sheets are evident from the material characterization via Raman spectroscopy, XRD, TEM-SAED, and XPS analyses. Here, we report a combination of the attractive conducting polymer polyaniline (PANI) with the as-prepared graphene for supercapacitor applications, where the PANI/graphene nanocomposites with different aniline concentrations (PANI1.125/G, PANI4.5/G, and PANI9/G) have been prepared via in-situ polymerization of aniline in the graphene dispersion. The structure and morphology of the nanocomposites are investigated using different characterization techniques which revealed that the molecular structure of the PANI is retained in the nanocomposites even with a strong interaction with graphene. FESEM and TEM images revealed the good coverage of graphene sheets with PANI that limit the volume change of PANI during the repeated charge-discharge processes. Electrochemical studies showed that PANI4.5/G has the highest specific capacitance of 126.16 mF/cm2 at a current density of 1 mA/cm2, resulting from the perfect combination of the pseudocapacitance behavior of the PANI along with the electrical double layer capacitance of graphene. A symmetric supercapacitor device is also fabricated with PANI4.5/G, which showed the highest areal capacitance of 116.38 mF/cm2 similar to that with three-electrode studies and also good cycling stability with 87 % capacitance retention in the specific capacitance after 6000 cycles. It also exhibited an energy density of 16 µWh/cm2 (0.29 Wh/kg) and a power density of 3.99 mW/cm2 (72.72 W/kg).

Damage of thin target plates impacted by conical projectiles with varying apex angles in ballistic application: experimental, FEA and ANN integrated approach

In the current study, an experimental setup consisting of smoothbore 30-caliber powder gun was employed to launch spherical projectiles (3 g/ϕ9) in the ballistic range of velocities from 500 to 1700 m/s and obliquity (0, 33 and 65°), impacting 2 mm thin Steel 1006 target plates. Crater dimensions (major and minor dia.) obtained from series of FE simulations run for the above configuaration was validated by corresponding experimental data. Subsequently, a fullscale 3D FE model considering 8-noded hexahedral elements was used to discretize SS304 conical projectiles (replacing spherical projectile) with various apex angles viz. 40°, 60°, 80° and 100° impacting on single (3 mm) and double layer (1.5 mm each) steel 1006 targets (replacing 2 mm target) in LS dyna. The material behavior was characterized using J–C strength and damage models, along with Gruneisen Equation of State. An erosion algorithm was used in the explicit FE code LS-DYNA to remove undesirable elements. In the next stage, Adam and Nadam optimizers have been employed in ANN models developed using Python code within the Tensor-Flow framework. The Keras Tuner library in the Tensor-Flow framework was used for hyper parameter tuning. The ANN models trained using simulation data successfully predicted the residual KE of conical projectiles with intermediate apex angles of 90°, 70°, and 50° across twelve different impact scenarios. The models with Adam and Nadam optimizers achieved mean squared error (MSE)/coefficient of determination (R2)/mean absolute percentage error (MAPE) values of 109.44/0.998/6.72 and 91.19/0.998/7.76, respectively.

Comprehensive study on epitaxial growth of GeSn(111) layers with high Sn content on Si(111) featuring Ge buffer layer

The study comprehensively discussed the crystalline properties of GeSn(111) epitaxial layers on Si(111) using Ge double buffer layers toward the formation of the direct transition GeSn(111) with a Sn content around 10%. We found that the introduction of Ge double buffer layers is rather effective to improve the crystallinity of GeSn(111) than the single buffer case. However, thicker Ge buffer layer degrades the crystallinity of GeSn(111) because the strain relaxation of GeSn layer is likely to occur. In this study, through optimizing the thicknesses of Ge buffer layers formed at low and high temperatures (LT-Ge and HT-Ge, respectively), it was clarified that 100 and 500 nm for LT- and HT-Ge thicknesses, respectively, are suited to realize a high quality GeSn(111). The grown GeSn(111) epitaxial layer includes a Sn content of ~8–11% with a compressive strain of ~1–2%, which is contained within the region of direct transition GeSn(111).

A novel acoustic micro-perforated panel (MPP) based on sugarcane fibers and bagasse

Natural materials are becoming a reliable alternative to traditional artificial materials used in sound absorption insulation. The present study was conducted to investigate the acoustic insulation of micro-perforated panel (MPP) based on sugarcane fibers and bagasse as an available and environmentally friendly material. The absorption properties of single- and double-leaf natural micro-perforated panels (MPP) made of bagasse and also nonnatural MPPs made of Plexiglass were measured using an impedance tube based on ISO 10534–2. Then the effect of bagasse and sugarcane fibers composite on the air gap of MPP was investigated. The results showed the peak sound absorption of the bagasse composite is in the range of 1000 to 2000 Hz, and the sugarcane fiber composite has a higher sound absorption coefficient than the bagasse composite. Also, natural MPPs have a higher absorption coefficient than nonnatural MPPs at all frequencies, and as the panel thickness increases, the peak absorption coefficient shifts to lower frequencies. The peak sound absorption coefficient of double-leaf MPPs made of bagasse is 76%, in the range of 160 to 200 Hz. Using sugarcane fiber composite in the air gap of single- and double-leaf natural MPPs causes the absorption peak to shift to frequencies below 100 Hz. According to the results, natural MPPs have a high sound absorption coefficient at low frequencies. These panels can control sounds with much lower frequencies, especially in a double layer and along with cane fiber composite in their air gap.

Assessment of electrochemical removal mechanisms of diverse transition metal dichalcogenides for caesium ion removal in wastewater treatment

Abstract Effective treatment of radioactive wastewater is crucial for broader nuclear energy adoption, with caesium radionuclides (most exist in the form of caesium chloride) presenting challenges due to their long half-life and biological hazards. Conventional adsorbents like zeolites and carbon-based materials, including graphene, face limitations in adsorption capacity due to the formation of electric double layers (EDL). This has led to the investigation of alternatives such as transition metal dichalcogenides (TMDs) e.g., MoS2, MoSe2, and WSe2, which offer promising galleries for caesium ion removal. Aside from extensively studied MoS2, there is limited research on the adsorption mechanisms and capacities of other TMDs like MoSe2 and WSe2. Here, we conduct a comparative study examining the removal mechanisms and capacities of exfoliated MoS2, MoSe2, and WSe2 nanosheets, alongside an evaluation of these properties in relation to graphene. Our investigation reveals distinct removal mechanisms and capacities among these three materials for capturing caesium ions in a variety of mechanisms. MoS2 nanosheets primarily utilise a pseudocapacitive charge storage mechanism via intercalation, as evidenced by a total charge storage of 0.78 C g1, with only 2.6% stored via EDL formation. In contrast, MoSe2 predominantly relies on EDL formation, with almost 60% of the total 0.54 C g1 charge storage attributed to this mechanism. Lastly, WSe2 exhibits a combination of both charge storage behaviours, with a total charge storage of 0.77 C g1, of which 14% is due to EDL formation. This research highlights the potential efficacy of TMDs as viable materials for caesium removal, offering an appealing alternative to conventional adsorbents and likely fostering advancements in water treatment technologies.

Preferred crystal surface exposure and near-crystal surface desolvation construct efficient Zn plating/stripping reversibility

The Zn/electrolyte interface stability is related to HER, passivation, dendrites, corrosion and Zn2+ deposition orientation. Reducing the occupation of H2O dipoles in the inner layer of electrical double layer (EDL) is conducive to the inhibition of interfacial side reactions and directing the deposition of Zn2+ along the (002) crystalline surface, which are beneficial to the reduction of dendrites and the improvement of plating/stripping reversibility. A mechanism is elucidated by which Acetyl-L-carnitine Hydrochloride (A-L-CN) reconfigures the EDL structure and guides the selective deposition of Zn2+ in this paper. Theoretical calculations show that A-L-CN can cover the high-energy active sites on the Zn (101) crystal plane and control the specific crystal orientation of the deposits along the (002) crystal plane to produce faceted epitaxial growth. The electrochemical test results show that the Zn anode has excellent plating/stripping reversibility as well as good cumulative capacity (10 mA cm−2, 1 mA h cm−2, ACE of 99.80 %, CPC of 7,753 mA h cm−2). The assembled Zn2+ hybrid supercapacitor (ZHS) and Zn//PANI full cell show excellent performance (ZHS up to 60,000 cycles; the capacity retention ratio of Zn//PANI full cell is 76.7 % after 1,000 cycles). The work offers the possibility of achieving stabilized Zn/electrolyte interface performance.

(Digital Presentation) Investigation of Nanoconfined Wet Etching Mechanism Using MD Simulation

With the advancement in semiconductor technology, multi-dimensional geometries are being formed resulting in nanoconfined spaces. It is very difficult to etch these nanoconfined spaces uniformly across different critical dimension (CD) sizes by wet processes, where typically the etch rate (ER) decreases in narrow CDs. One of the mechanisms is the electric double layer (EDL) model, which prevents etchants from entering the nanochannels due to the overlapping of the EDL. In previous experiments, it was reported that mixing an organic solvent with an etching solution does not decrease the ER in narrow CDs. The EDL model alone cannot fully explain the mechanism in organic solvents, and other factors need to be considered. In this paper, we report the results of investigating the etching mechanism in water and organic solvents in nanoconfined spaces by calculating number density distribution and diffusion time using molecular dynamics (MD) simulations.

Harnessing the potential of MOF/Fe2O3 nanocomposite within polypyrrole matrix for enhanced hydrogen evolution

This study investigates the influence of pyrrole concentration and the addition of MIL53(Al)/Fe2O3 nanocomposite on the hydrogen evolution reaction (HER) activity of polypyrrole (PPy) electrocatalysts. Electrodeposition of PPy on a nickel (Ni) substrate was conducted using various pyrrole concentrations ranging from 0.01 M to 0.2 M, followed by evaluation through linear sweep voltammetry (LSV) experiments. Results indicated that PPy synthesized with 0.1 M pyrrole exhibited the highest HER activity, characterized by lower onset potential and higher current density. Additionally, the incorporation of MIL53(Al)/Fe2O3 nanocomposite into PPy coating enhanced electrode performance, evidenced by high charge transfer kinetics. Nyquist diagrams and electrochemical impedance spectroscopy (EIS) analysis confirmed accelerated electron transfer kinetics and lower charge transfer resistance for PPy@MIL53(Al)/Fe2O3 compared to Ni substrate. Despite a lower electrochemical double layer capacitance (Cdl), PPy@MIL53(Al)/Fe2O3 demonstrated enhanced catalytic activity, underscoring the importance of electrode morphology and active site characteristics. Furthermore, stability tests revealed consistent performance of PPy@MIL53(Al)/Fe2O3 over prolonged electrolysis periods, highlighting its potential for practical applications in hydrogen generation.

Evaluation of the Solid-Electrolyte Interphase Formation in a Bis(fluorosulfonyl)amide Based Ionic Liquid in the Presence Lithium Ion Using Different Redox Probes

The SEI formation in 0.5 M LiFSA/BMPFSA was investigated using different redox probes. The redox reaction of a metallocene and organic compound on a Pt electrode were investigated by cyclic voltammetry in BMPFSA and 0.5 M LiFSA/BMPFSA. Cyclic voltammograms were taken after holding the electrode at different potentials for 1 h. The cyclic voltammograms were unchanged in BMPFSA, indicating that BMPFSA was stable in the measured potential range and that the redox reaction was not affected by a change in the electric double layer structure. On the other hand, peak shifts were observed in the presence of Li+ at potentials more negative than –1.1 V vs. Ag|Ag(I), attributed to a decrease in the electron transfer rates and indicating that the SEI formation promoted by the interaction between Li+ and FSA– affects the redox reactions not only of metallocene but also of organic compounds that undergo outer sphere electron transfer reactions.

High responsivity zero-biased Mid-IR graphene photodetector based on chalcogenide glass waveguide

Graphene’s unique properties have made it a promising material for high-performance photodetectors due to its interesting features including broadband absorption, fast speed, and strong photothermoelectric effect. Here, an optimized waveguide photodetector incorporating double graphene layers with two cores is presented to boost the responsivity (∼twice), at Mid-IR range. The proposed structure operates in the zero-bias regime to eliminate the dark current issue associated with the zero bandgap nature of graphene and leads to lower noise equivalent power. The presented photodetector operating based on split gates to electrostatically induce the p-n junction in graphene channels, operates based on the photothermoelectric effect and provides responsivity, NEP, and 3 dB bandwidth of 6.3 V/W, 0.34 nW/Hz1/2, and 1.54 GHz, respectively for the detection at λ = 5.2 μm. The feasibility of the proposed structure is proved according to recent experimentally demonstrated photodetectors. Hence, the obtained results are reliable, in practice. The study has been accomplished by numerical simulation of mode profiles and solving the heat equation to extract the characteristics of the proposed photodetector. The zero-power consumption and tunability of the proposed structure make it a promising candidate for sensing, industrial, defense, and environmental monitoring applications with high accuracy.

Interaction between the electrochemical properties of powdered activated carbon and the biochemical processes within bacteria in Azo dye biodecolorization: An explanatory mechanism

Drawing on prior reports highlighting the redox mediator properties of powdered activated carbon (PAC), this study was designed to evaluate these properties to enhance the decolorization of azo dye by Klebsiella quasipneumoniae GT7. It was found that the presence of 0.5 % PAC in the medium increased the biodecolorization rate early in incubation. Chemical analysis revealed that dye conversion into aromatic amines occurred in microbial systems both with and without PAC. However, at initial dye concentrations (Cid) of 2 mM or higher, some dye remained on the PAC surface and in the medium. In contrast, the PAC-free system achieved nearly 100 % biodecolorization at all initial dye concentrations. The negative impact of PAC on decolorization efficiency in microbial systems with high initial dye concentrations cannot be solely explained by its redox mediator function. This study used the amphoteric-Donnan model for PAC's electrical double layer (EDL) and Mitchell's chemiosmotic model for bacterial proton motive force (PMF) to explore this. It found that charge storage in PAC's EDL regulates electron transfer fluxes, and proton species enhance the proton motive force across the bacterial membrane. These observations improve the understanding of PAC's role in microbial decolorization and its potential future applications.

Internal quantum efficiency improvement of InGaN-based red LED by using double V-pits layers as strain relief layer

Micro/mini light emitting diodes (LEDs) based on AlInGaN material system have vast potential in display applications. Nevertheless, the low internal quantum efficiency (IQE) of InGaN-based red LED limits its development and application. In the epitaxial structure of our designed red LED, double V-pits layers were used as strain relief layers to reduce compressive strain and improve the IQE of the active layer. First, InGaN/GaN superlattices (SLs) were grown below the active layer to form low-density large V-pits layer. Subsequently, multi-period green and red composite quantum wells were adopted as the active layer. A high-density small V-pits layer was introduced into the active region to release the compressive strain by adjusting the growth parameters of green multiple quantum wells (MQWs). The V-shaped pits divide the continuous large-area of active layer into mutually isolated small pieces, which prevents the transmission of strain and converts the long-range strain into separated local strain. The peak IQEs of LED A2 with single V-pits layer and LED B4 with double V-pits layers were measured to be 10.5% at 613 nm and 21.5% at 612.1 nm, respectively. The IQE is greatly improved by 204.7%. The research results indicate that the double V-pits layers structure can alleviate the compressive strain of InGaN QWs more effectively, reduce the influence of piezoelectric polarization field, and improve the IQE.

PhiX-174 phage concentration in rainwater by skimmed-milk flocculation

ABSTRACT Rainwater, as a sustainable source of drinking water, is becoming increasingly important worldwide. Appropriate microbiological techniques are needed to ensure the acceptability of rainwater for potable uses. Bacteriophage has been widely used as a viral indicator in water studies, and its concentration is an important step when sampling several litres of water. Skimmed-milk flocculation (SMF) is a simple method for viral recovery, and its efficiency has already been assessed for some viruses. However, there are only a few records on bacteriophage recovery using SMF, and none with PhiX-174 coliphage, an important surrogate for human enteroviruses. Thus, this work aimed to evaluate the effectiveness of the SMF technique on the concentration of PhiX-174 coliphage in rainwater. 3 L of rainwater samples were artificially spiked with PhiX-174 and were concentrated to 10 mL volumes by SMF. The phage enumeration on the concentrated samples were evaluated by a standard double layer plaque assay. From the 6 samples tested, the average recovery was 22.8 ± 15.2%, ranging from 10.8 to 52.8%. This is the first time that SMF is applied for PhiX-174 coliphage recovery, and in rainwater. Therefore, SMF is a cost-effective method that can effectively be used to recover bacteriophage PhiX-174 in water samples.

Ni4Nb1.8W0.1Ti0.1O9: Stabilization of the I-Type Ni4Nb2O9 Structure and First Magnetic Study of This Corundum-like Compound.

For the first time, we report on the structural and magnetic properties of a polycrystalline sample of Ni4Nb2O9 from I-type (Fdd2), obtained by the partial cosubstitution of Nb5+ by Ti4+ and W6+. The crystal structure is investigated by combining synchrotron X-ray, neutron, and electron diffraction at room temperature. This I-type structure is derived from the corundum-like Ni4Nb2O9 II-type (Pbcn) and is noncentrosymmetric and polar. The Ni-lattice is composed of the stacking of distorted honeycomb layers with double zigzag ribbons 60° disoriented from each other in two successive double layers. The connection between layers is ensured by the sharing of octahedra faces building (Nb,W,Ti)2O9, Ni2O9, and Ni3O12 units. This study shows how the disruption of the Nb2O6 units by smaller d0 cations impacts the structure, significantly modifying the Ni network and, thus, the magnetic properties. The latter were studied by dc- and ac-magnetic susceptibility, and the magnetic structure was solved by neutron powder diffraction. A ferrimagnetic behavior occurs below 68 K, followed by a re-entrant spin-glass-like behavior below ≈50 K.